#include <iostream>

class Singleton{
public:
    static Singleton _singleton;
private:
    int _data;
    Singleton(int data = 0) :_data(data){ std::cout << "单例 饿汉模式 构造!\n"; }
    Singleton(const Singleton &) = delete;
public:
    static Singleton& get_instance() {
        return _singleton;
    }
};

Singleton Singleton::_singleton;

int main() {
    
    return 0;
}
